1. Technical Field
The present invention relates generally to hand-held dental instruments, and more particularly to hand-held dental mirrors which are illuminated by fiber optic light sources.
2. Background Art
The dental mirror has long been and continues to be a prolific instrument in the clinical fields of dentistry. In the last 30 years, the dental industry has sought to develop a mirror with its own illumination system. Examples of such mirrors are disclosed in U.S. Pat. Nos.: 3,638,013 to Keller; 4,279,594 to Rigutto; 4,629,425 to Detsch; 4,993,945 to Kimmelman et al.; 5,139,420 to Walker; 5,139,421 to Verderber; and 5,457,611 to Verderber. The most successful of these mirrors have been those which contain a light source built in the handle of the mirror. The mirror disclosed in U.S. Pat. No. 5,457,611 to Verderber is such a device; it is the only known illuminated mirror that has been succesfully marketed. The Verderber mirror is currently produced and marketed by Welch-Allyn, Inc., of Skaneateles, N.Y.
The problem with illuminated mirrors having built-in light sources is that the handle or handpiece supporting the mirror heats up to a temperature that is uncomfortable to the user. As a result, the user (e.g., a dental clinician) may have a tendency to put the mirror down repeatedly during clinical procedures. Also, the clinician may be inclined to alternate mirrors during longer procedures to avoid the discomfort. These practices invariably prolong procedures, distract the clinician, and compromise accuracy, all to the detriment of the patient.
A solution to the heat problem is proposed in U.S. Pat. No. 5,457,611 to Verderber. In Verderber, a high intensity lamp is contained in a heat sink mounted within the dental mirror handle. The handle contains multiple vents spaced from and surrounding the heat sink. Heat from the lamp radiates out through the vents from the heat sink. This convection creates a thermal current, causing heated air to exhaust through the vents and be replaced by cooler air from the surrounding atmosphere (hereinafter referred to as xe2x80x9cambient coolingxe2x80x9d). Even with the aid of ambient cooling, the heat generated by the lamp becomes particularly noticeable within 15 minutes. Handle temperatures for the Verderber mirror have reached 134xc2x0 F., which are uncomfortable and distracting to the clinician.
Another approach to cooling a dental handpiece is disclosed in U.S. Pat. Nos.: 4,334,863 to Magid et al.; 4,477,252 to Lieb et al. and 3,634,938 to Hutchinson. Magid et al. discloses cooling the lamp, in part, by passing water and air through parallel channels adjacent to the lamp (FIG. 4). This approach is not sufficient by itself to prevent the handpiece from becoming uncomfortably hotxe2x80x94a critically dimensioned air gap and shield are also required. Lieb et al. discloses cooling the lamp (FIGS. 4 and 6) with exhaust air from a turbine drill; the exhaust air passes adjacent to and around the lamp.
In Hutchinson, cooling is accomplished by a water coil around the lamp (FIG. 3) and an air circulating chamber; water and air used for operating a turbine drill is passed through the coil and chamber, respectively, to effect the cooling. None of these approaches are particularly suitable for improving or retrofitting with the commercially produced dental mirror disclosed in U.S. Pat. No. 5,457,611 to Verderber.
A longstanding shortcoming inherent in a dental mirror is the tendency of the reflective surface to become obscured during clinical procedures. Fog, mist, spray from dental drills, tooth debris, dental materials, etc., collect on the mirror""s reflective surface, impairing the visibility of the image from the mirror. The need for clear mirrors in dental and otolaryngology offices is immense. The affected procedures range from hygiene procedures (which are an important and constant activity in the dental office) to extensive oral surgeries as well as medical office examinations.
Clinicians are forced to repeatedly clean or wipe the reflective surface, which requires repositioning of the mirror. This repeated repositioning, however, can disrupt the concentration of the clinician, leading to reduced accuracy. Furthermore, much time is lost by the clinician in removing the mirror from the patient""s mouth, cleaning or wiping the surface, then repositioning the mirror in order to continue with the procedure.
As a result of all of this, some clinicians opt not to use a dental mirror at all. Instead, they position the patient at an angle that allows for a more clear and direct view of the procedure. However, the clinicians must awkwardly position their heads, necks and backs to achieve such a view. Discomfort and strain are often experienced by both the clinician and the patient. Clinicians may develop temporary or even permanent neck and back problems as a result of such practices.
Attempts have been made to automatically clear (or xe2x80x9cself-cleanxe2x80x9d) the mirror with a flow of air and/or water. Examples of such attempts are disclosed in U.S. Pat. Nos.: 5,449,290 to Reitz; 5,139,420 to Walker; 4,925,391 to Berlin; 4,629,425 to Detsch; 4,279,594 to Rigutto; and 3,969,824 to Widen et al. The mirrors disclosed in these patents do not contain a light source in the handle; and thus, there is no suggestion that the air and/or water used to clean the mirror may also be used to cool the handle. In addition, there is no coincidental warming of the air/water by an onboard light source before the air/water is applied to the mirror. While these self-cleaning approaches are theoretically sound, they have not, to this inventor""s knowledge, been commercially successful. Further, there is no suggestion that such approaches be especially adapted for the commercially produced dental mirror disclosed in U.S. Pat. No. 5,457,611 to Verderber. Verderber discloses no provision for self-cleaning or defogging the mirror.
Another problem with dental mirrors is that their reflective surfaces are susceptible to marring by tooth debris, dental materials, or aluminum oxide powder from air-abrasion systems. When such marring occurs, the mirror must be replaced. This adds to the cost of treating a patient, which cost is passed on to the patient. In self-cleaning systems using a flow of water, the mirror is coincidentally protected from abrasion, to some degree, by the water; however, water, as a protection mechanism, creates two new problemsxe2x80x94(1) distortion of the image from the mirror, and (2) the need to evacuate the water.
In some situations, it may be desirable or necessary to quickly replace the handle of an illuminated dental mirror during a procedure (e.g., if the lamp burns out or some other electrical malfunction occurs). As disclosed in U.S. Pat. No. 5,457,611 to Verderber, the handle of the mirror is connected to an electrical cord which supplies electrical power to the lamp. In order to separate the handle from the cord, a rear end cap must be unsnapped (FIG. 2) or unscrewed (FIG. 5) from the body of the handle. Such separation mechanisms are not expedient when a quick handle replacement is necessary during a clinical procedure.
A further problem with dental mirrors is the risk of transmitting germs from one patient to another (i.e., xe2x80x9ccross contaminationxe2x80x9d). Cross contamination is possible because the handle of the mirror is exposed to the patient during clinical procedures. The recommended approach for preventing cross contamination is to autoclave the mirror handle after each use. Such an approach is time consuming and requires access to and handling of autoclave equipment and materials. Further, the autoclave process increases the wear-and-tear on the mirror handle.
It is therefore an object of the present invention to provide display apparatus and methods that avoid the limits and problems associated with the prior art.
It is another object of the present invention to maintain the temperature of a dental handpiece, containing a light source, at comfortable levels during clinical procedures.
It is a further object of the present invention to improve upon the dental mirror disclosed in U.S. Pat. No. 5,457,611 to Verderber.
It is yet another object of the present invention to provide certain retrofittable components for the dental mirror of U.S. Pat. No. 5,457,611.
It is yet a further object of the present invention to provide a self-cleaning and self-defogging dental mirror.
It is still another object of the present invention to cool a dental handpiece, containing a light source, using compressed air from a standard dental office air-supply.
It is still a further object of the present invention to utilize the compressed air, after it has been warmed during the cooling process, to also clean and defog the mirror.
It is yet still another object of the present invention to reduce marring of the reflective surface of the dental mirror by directing the compressed air onto the reflective surface in a fan-like pattern.
It is yet still a further object of the present invention to provide an expedient means for interchanging dental mirror handles.
It is yet still a further object of the present invention to effectively eliminate the risk of cross-contamination associated with the use of dental mirrors.
These and other objects are attained in accordance with the present invention wherein there is provided an illuminated dental mirror instrument comprising a handle, a mirror, an elongated tubular member, an electric light source, a light transmitting element, a thermally conductive fluid conduit, a fluid discharge manifold, a manifold support member, first and second complementary connectors, and a combined electrical and fluid supply line.
The handle of the instrument is defined as having front and rear ends. The mirror contains a reflective surface and includes a shank portion which is releasably attached to the front end of the handle. The elongated tubular member is located within the handle. The light source is contained within the elongated tubular member. The light transmitting element transmits light from the light source to the front end of the handle. The thermally conductive fluid conduit is coiled around the elongated tubular member, and the conduit is defined as having an intake end and a discharge end.
The fluid discharge manifold of the instrument is coupled to the discharge end of the fluid conduit via a fluid tube. The manifold support member is removably secured to the shank of the mirror and supports the manifold adjacent to the reflective surface of the mirror. The fluid tube is supported by the support member. The manifold is configured to discharge fluid in a fan-like pattern over the reflective surface of the mirror.
The first connector of the instrument is removably connected to the rear end of the handle, and it contains a fluid passage removably coupled to the intake end of the fluid conduit. The light source is mounted to the first connector.
The second connector of the instrument is removably connected to and mates with the first connector. The second connector contains a fluid passage removably coupled to the fluid passage of the first connector. The second connector includes electrical conductors which are removably electrically coupled to the light source.
The combined electric and fluid supply line is coupled to the second connector and serves to couple electrical energy and fluid to the electrical conductors and fluid passage, respectively, of the second connector.
In another aspect of the present invention, there is provided a method of retrofitting a dental mirror instrument. The instrument is of the type having: (i) a handle containing a plurality of vents; (ii) a mirror with a reflective surface coupled to the handle; (iii) an elongated tubular member located within the handle; (iv) an electric light source contained within the elongated tubular member; (v) a light transmitting element for transmitting light from the light source to the mirror; (vi) an end cap removably attached to the handle; and (vii) an electrical cord, secured to the end cap, which includes a pair of wires coupled to the light source.
The method of retrofitting the instrument comprises the steps of: (a) removing the light source, end cap and electrical cord from the handle; (b) removing the elongated tubular member from the handle; (c) placing a thermally conductive, helical-shaped, fluid conduit around the elongated tubular member to create a subassembly, the fluid conduit having an intake end and a discharge end; (d) installing the subassembly in the handle, such that the discharge end of the fluid conduit is accessible through a vent in the handle; (e) coupling a fluid discharge manifold to the discharge end of the fluid conduit; (f) attaching a support member to the instrument and using the member to support the discharge manifold adjacent to the reflective surface of the mirror; (g) replacing the light source, end cap, and electrical cord of the instrument with a replacement light source, first and second connectors, and a supply line, the replacement light source being mounted to the first connector and the supply line being mounted to the second connector; (h) inserting the replacement light source into the elongated tubular member; (i) connecting the first connector to the handle, in place of the end cap; and (j) connecting the second connector to the first connector.
In a further aspect of the present invention, a protective contaminant-resistant sheath assembly for a dental instrument is provided. The assembly comprises a support and an elongated protective sheath. The support is adapted to be coupled to the dental instrument. The protective sheath is made from a flexible contaminant-resistant material. The sheath has a first end secured to the support and a second end. The second end is open and free to allow manual deployment of the sheath over and around at least a portion of the dental instrument.